Brendan Enrick

Daily Software Development

Flags Over Objects

If you didn’t notice it, our “flag” month was the same month as Independence Day in the United States. We celebrate that day with flags, fireworks, and a lot of cookouts. Notice anything in the picture? Yep. We’re missing the fireworks. Anyway, the topic of Flags Over Objects is an important one.

Flags Over Objects is the Software Craftsmanship Calendar’s anti-pattern topic in July 2014. As a developer, I am sure that you’ve come across code where boolean values (flags) were used far too much. This is often a misuse of state. Plenty of times there is a better, simpler way of handling the state of objects.


In this image, you might notice (looking carefully) a few obvious (and common) issues with using flags. First, you’ve got a whole list of checkboxes even though some of those can only ever be one at a time. You might also notice that there are a lot of repeats of the same checkbox.

Are you using this anti-pattern anywhere?